1. Technical Field
The present disclosure pertains to a type of indwelling needle that is used in transfusion and blood collection for piercing and indwelling in a blood vessel of a patient.
2. Background of Related Art
In the prior art, indwelling needles have been used in various applications, such as hemodialysis or feeding of prescribed medicine solutions, etc. The indwelling needle includes an external needle having a needle tip for indwelling in a blood vessel of a patient and an internal needle that is inserted into the external needle to facilitate smooth piercing of the blood vessel of the patient. In operation, the internal needle is inserted into the external needle such that the tip portion of the internal needle protrudes from the tip portion of the external needle. Thereafter, together with the internal needle, the external needle pierces the blood vessel. Then, while the external needle indwells in the blood vessel, the internal needle is pulled out of the external needle (blood vessel), and a tube member or the like for feeding prescribed blood or medicine solution or the like is connected to the rear end portion of the external needle, and hemodialysis or feeding of a medicine solution or the like is carried out.
In the indwelling needle, there is a needle tip protective part for preventing the patient from being harmed by the needle tip of the internal needle which is pulled out of the external needle. The needle tip protective part has a tapered cylindrical body with an inner diameter larger on one end and smaller on the other end. The tip portion of the internal needle protected by the needle tip protective part is formed of a size that permits it to be inserted into the opening on one end of the needle tip protective part but not into the opening on the other end. Consequently, when the internal needle is pulled through the needle tip protective part, the tip end of the internal needle cannot pass through the opening on the other end of the needle tip protective part. Thus, the needle tip protective part is coupled to the tip portion of the internal needle and the tip portion of the internal needle is covered.
However, the aforementioned needle tip protective part of the prior art is prone to shifting position to the rear side of the internal needle. Consequently, the tip portion of the internal needle may be exposed. People have proposed a type of indwelling needle having a needle tip protective part that makes use of a spring member or the like to fix the protective part at the tip portion of the internal needle so that the tip portion of the internal needle can be reliably covered. However, for the indwelling needle, the number of parts increases, the manufacturing cost rises, and the resistance when the internal needle is pulled out of the external needle becomes higher, leading to poor operability. This is undesirable.
The purpose of the present disclosure is to solve the aforementioned problems of the prior art by providing a type of indwelling needle that has a simple structure, good operability, and can have the needle tip protective part mounted reliably on the tip portion of the internal needle.